CVE-2026-6736: GitHub Enterprise Server · Missing Authentication
Affects GitHub Enterprise ServerSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium · fixed in 3.20.2 : update GitHub Enterprise Server when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.20.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 7 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| GitHubEnterprise Server | Affected
| Fixed in– |
AI-suggested
This vulnerability is fixed in GitHub Enterprise Server versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18. Users should upgrade to one of these fixed versions or later to remediate the issue. Since this is not a cloud service, patching the affected server instances is required. Patch status is confirmed by the vendor advisory information embedded in the description.
Description
CVE-2026-6736 is an authentication bypass vulnerability in GitHub Enterprise Server versions prior to 3.21. It allows an unauthenticated attacker to create a local user account despite external identity provider enforcement. The vulnerability occurs because the signup endpoint does not properly enforce authentication restrictions when external authentication is enabled. The attacker can establish a session with default base permissions on the instance. Exploitation requires network access to a vulnerable GitHub Enterprise Server instance configured with an external authentication provider. The issue was fixed in versions 3.20.2, 3.19.
References
- docs.github.com/en/enterprise-server@3.16/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.17/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.18/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.19/admin/release-notes (opens in a new tab)
- docs.github.com/en/enterprise-server@3.20/admin/release-notes (opens in a new tab)